Fluid-pressure brake system.



W. SAUVAGE. FLUID PRESSURE BRAKE SYSTEM.

APELIOATION FILED MAY 28, 1908.

Patented 0013.27, 1908.

2 SHEETS-SHEET 1.

Inventor:

W. H. SAUVAGE. FLUID PRRssURR BRAKE SYSTEM.

APPLICATION FILED MAY 28, 1908.

Patented 0ct.27,1908.

2 SHEETS-SHEET 2.

. v R w v A Uni No. 902,114. I

r lipplication which the following is a specification,'refer-. encebeing had to the accompanying drawin s, forming a part hereof.

t is well understood that in the operation of fluid pressure brakesunder certain conditions, as when a train is descending a long,

steep grade and brakes must be continuously applied, it is necessary torecharge the aux' iary reservoirs from time to time, and that in orderto accomplish this the engineer must have moved his valve to fullrelease position, which would effect the release of the brakes but forthe provision, on each car of the train, of a retaining valve. Thisvalve, which is ordinarily out of 0 eration, is usually set by thetrainmen efore the train reaches the top of the grade and thereafterserves to maintain a predetermined pressure in the brake cylinder,notwithstandin the movement of the engineers valve to fu 1 releaseposition, so that the brakes are continuously set with some pressure,though not the maximum, and the s eed of the train is therefore steadiedand oss of control is prevented. Nevertheless, by reason of loss ofpressure through dancing of the retaining valve upon its seat,occasioned by the vibration of the car, and from leakage at variouspoints throughout the system, the pressure under which the brakes areheld when the engineers valve is moved to full release posi tion oftenand in fact usually falls more or less below. .the predetermined.rninirnum which is intendedto. be preserved by the re taining valve. y

It is the object of the present. invention, therefore, to provide meansfor automatically restoring .this pressure, whenever, from.

any cause, it falls-below such predetermined minimum and therefore toprevent the consequences of the reduction of pressure from the causesnamed onfrom any other cause.

Other objects of the invention, incidental.

or subordinate tothis main object, will be referred to hereinafter. 1

In accordance with the invention there are provided means adapted to beoperated by WILLIAM n2. siruv i'epjor NEW'YORK,

. rnmn-rnnssunnannercs sYs'rEii/r; Ila v Specification ofjLettersPatent.

,llieos. Serial massage. I

deficiency of pressure in the brake cylinder toadmit more pressure.directly from the source ofpressuresupplied independently of theoperation of ..,.th e, usual t1iple,;.V=l1Ve.

Such means maybelocated in different relations with respect; =to1thegusual ,elements of. ,so the brake system andwwhile, incejrtainj-relations, they may, :possess; added vfunctions, nevertheless, in allzofsuch relations theypos i sess the principal function, already referred;to, of automatically restoring pressure in the .65 brake cylinder.

The invention will be more fully explained hereinafter with reference tothe accompanying drawings. in ;which several different embodimentsthereof are .illus,tra.ted-,-;and,- in J Figure 1 is ad'iagram matic. oroutline .view of so much of anordinary fluidbpressure brake system, asis necessary to. enablethe application of the invention to beunderstood, the automatic pressure restoring .device being represented,asconnected between the train pipe and the retaining valve .pipeg. Fig.2 is a similar view, but showing theautomatic pressure restoring deviceconnected. between the brake; cylinder epipe and the train pipe. Fig: ofan ordinary: taining,valve,-such-,as may. be employed in;connectioniwith. the inven-j: tion. Fig. 4 is' adetail view, section,showing a triplevalve of ordinaryconstruction with the automaticrestoring device suported directly thereon, a portion of the auX- iliaryreservoirbeing also shown. Fig. 5 is a detail view, in section, of theautomatic pressure restoringudevice, on a larger scale than that of Fig.4. 111. re a The structure :shown in the, drawings, v cept withrespeotto the nowek features here inafterpointed; out,.-is of theordinary.eharae I ter of fluid pressure brakeicorfstructibn,- andcomprisesa train pipe a, a brake cylinder 5, anauxiliary reservoir-,0, atrain pi e connection a between the train pipe an the tri 1e valve (1, abrake cylinder connection b, e tween the triple valve (Z and the brakecylinder 1), indicated as passing through the auxiliary reservoir,,asusual, auretaining, valve e, and a connection e ,frorrhthe exhau st of,the, triple valve to theretaining. valve, re; ,1 05 taining valve 0maybe ofusual construction, comprising, as shown in Fig. 3, a handoperated valve e which may be turned so as to permitthe exhaust of thetriple valve to communicate directly with the atmosphere, or tocommunicate with the atmosphere under, the control of a weighted valve.e which, under operative conditions, serves to maintain a predeterminedpressure in the brake cylinder. The triple valve d may also be of anyordinary or suitable construction, as indicated in Fig. 4 of thedrawings, for example, having a train pipe connection at a, a brakecylinder connectionb, an exhaust and retaining valve connectionsufficientlyindicated by the pipe e in Figs. 1 and 2, a piston (l, aslide valve (1 and other parts as usual.

The automatic pressure restoring devicef, a convenient and desirableconstruction of which is shown in detail in Figs. land 5, is adapted toreceive fluid under pressure from the .train pipe a and to transmit itto the brake cylinder, either directly or through the retaining valvepipe and. the triple valve. To accomplish this result it may be placedin different relation to the other elements of the b ake system and itmay be supported in di [rent ways. Thus, in Fig. 1, it is shown asconnected across from the train pipe connection 11- to the retainingvalve pipe c, being supported by the connecting pipes. In Fig. 2, it isshown as connected across from the train pipe a to the brake cylinderpipe I), being supported by the connecting pipes. In Fig. 4, it is shownas supported upon the casing of the triple valve, being connected to thetrain pipe through the passages of the triple valve and its connectionto the brake cylinder, either directly or through the retaining valvepipe, being indicated .by the connectionf.

Referring now to thedetails of construction of the automatic. pressurerestoring device represented'in the drawings and particularly 1n Figs:4and 5, it will be seen that the train pipe pressure is admitted to thedevice through a passage (1 formed by slightly fiattcning the pistonstem 11 of the triple valve, where it rests in the hole)" of theautomatic pressure restoring device. A restricted passage f, protectedby a check valve f, permit s the fluid under train pipe pressure toenter a valve chamber gfthe valve g of which is held normally againstits seat by aspring or other suitable means, which means inay yield topermit the valve to open, as when its stem extension (1 is acted upon bythe cam hereinafter mentioned, to permit the iluid under pressure topass into a chamber 71- and thence, through the connection f, to thebrake cylinder either directly, as in the arrangement indicated in Fig..2, or indirccttv through the triple valve, as in the arrangementindicated in. Fig. l. also in communieation with a phragm [t acted upon.in oppr.

" on or diamon in the fluid pressure mmimunicated from the chamfrom thetrain pipe until the piston is carried The chamber [bl S.

sides of the cam 71, which for convenience lits but travels freelywithin the chamber I). In Fig. 4, the piston h and a cam 71/ are shownin operative position, while in Fig. 5 they are shown in exhaustposition.

In 0 erat-ion, it will be understood that any ret notion of pressure inthe brake cylinder is immediately felt in the chamber 71 and that theiston 72? will be moved by the spring 72. toward the right against thereduced pres sure in the chamber h. Such movement of the piston causesthe cam h" to make contact with the extension g of the valve and toforce the valve from its seat, thereby per-' mitting the fluid undertrain pipe pressure to enter the chamber h and move the piston backagainst the spring 71 restoring the condition of e uilibrium andpermitting the valve to c ose again. The conditions just describedexist, of course, when the retaining valve is set to retain thepredetermined pressure, whlch predetermmed pressure \VI 1 be 'built upor restored from the train pipe as often as it is depicted by leakage orby dancing of the retaining valve. Such restored pressure is transmittedas usual to the brake cylinder either directly or through the triplevalve. W'hen, however, the triple valve is inoperative, so that no backpressure is retained in the retaining valve pipe or brake cylinder pipe,the piston h, not being resisted by fluid )ressure, will be thrown bythe spring h" rom the operative position shown in Fig. 4 to' the exhaustposition shown in Fig. 5. Assoon, moreover, as the back pres sure isreestablished in the pipe connectien f, the piston will be thrown backto operative position against the pressure of the s ring If. Themovement of the piston in either of the conditionslast referred to is sorapid that the openmg of the valve, 5/ by the passage 01' the cam 7f 1salmost instantaneous 'flong train pi e,' it often happens that whileReferring now particularly to the arrangement of the automatic pressurerestoring device with respect to the other elements of the brake system,shown in Fig. 2, in which said device is'not connected directly to theretaining valve, but is connected directly to the brake cylinder, and,through the triple valve, indirectly to the retaining valve, beingconnected between the train pipe a and the brake cylinder pipe I), itwill'be obvious that so far as concerns the accomplishment of the mainfunction, namely that of restoring the predetermined minimum pressure ini the brake cylinder when it is depleted, the operation of the automaticdevice is the same as already described. In this relation, however, thedevice has an additional function as an accelerator in building upquickly the brake cylinder pressure throughout the length of the train,thus securing a uick service application of the brakes in al parts ofthe train and reducing very materially the time of application of thebrakes where otherwise the brake pressure might notfbe built up quicklyto the desired degree. Thus,in a very long freight train, due to theleakage of pressure from the auxiliary reservoirs back through the feedgroove of the triple valve into the train pipe when the pressure thereinis released, and also by reason of the friction between the movingcolumn of fluid and the train pipe, it becomes an important factor in avery long train, and

.through-the retardation of thetransmission of pressure impulses throughthe length of a the brake cy inders of the cars near the head end of thetrain may have a good working pressure, the brake cylinders of the carsnear therear end of the train may have a very low pressure. reason ofthe direct connection from the train pipe to the brake cylinder pipethrough the automatic valve, the fluid will be drawn oil from the trainpipe at all points along its length into the brake -cylinders, andthereduction of pressure in the train pi e which is necessary to cause thetriple va ve to perform its proper functions is the soonerestablishedand the actionof the triple valve throughout the length of the train istherefore accelerated. On the other hand, through. the connection of thebrake cylinder pipe to the train pipe, whenever the Now it will be seenthat by pressure in the brake cylinder is less than the predeterminedpressure desired for the operation of the brake, the deficiency in suchpressure will be immediately restored directly from the train pipe.

Should the train pipe be ruptured, the check valve f will prevent theescape of fluid under pressure from the brake cylinder, being anecessary feature for this purpose in the arrangement shown in Fig. 2,but may be dispensed with in the arrangement shown in Fig. 1.

It will be obvious that various other changes in details of constructionand arrangement might be made without departing from the spirit of theinvention.

I claim'as my invention:

1. In a fluid pressure brake system, means operated by deficiency ofpressure in the brake cylinder and independent of the usual connectionthrough the triple valve to admit fluid under pressure from the trainpipe to the brake cylinder. I

2. In a fluid pressure brake system, the combination with abrakecylinder and means to supply fluid under pressure, of a connectionbetween the fluid pressure supply and the brake cylinder independent ofthe usual connection through the triple valve and means operated bydeficiency of pressure in the brake cylinder to admit fluid underpressure from said fluid pressure supply to the brake cylinder.

I3. In a fluid pressure brake system, the combination with a brakecylinder and train pipe, of a connection between the train pi e and thebrake cylinder independent of tie 'and means operated by deficiency ofpressure in the brake cylinder to admit fluid under pressure from thetrain pipe to the brake cylinder.

'5. In a fluidpressure brakesystem, the combination with a brakecylinder and a train pipe, of a connection from the. brake cylinder tothe train pipe independent of-the usual connection through the triplevalve, and a valve actuated by ieduction of pressure in the brakecylinder to admit fluid under pressure from the train pipe'to the brakecylinder.

6. In a fluid pressure brake system, the combination with a brakecylinder and a train pipe, of a connection between the train I pipe andthe brake cylinder independent of 1 This specification signed andwitnessed the usual connegtion thlllough the triple this-16th day ofMay, A. D., 1908. V8, ve, a, piston su jeet to t e )ressure in the l 7 1brake cylinder, means to moi e the. piston ILLIAM SAUVAGL' against a,reduced brake cylinder pressure In the presence ol and a valv A actuatedby the movement of the V. B. GREELEY, piston to admit fluid un rpressure. 5 AMBROSE L. OSum.

